1. Field of the Invention
The present invention relates especially to the laser beam optical scanning system of an image formation device which forms an electrostatic latent image on the photosensitive body by means of a laser beam.
2. Description of the Prior Art
The conventional image formation apparatus for laser beam printer and similar devices has a laser beam optical scanning system which scans across the surface of a photosensitive body with a laser beam that is radiated from a semiconductor laser or the like, wherein the sagittal image surface of the laser beam optical scanning system generally has a large bending. Moreover, the laser beam optical scanning system has a drawback in that the correction rate for the tilt of the mirror facets that are used in the laser beam optical system is reduced. Further, it was not possible to realize a satisfactory f.theta. characteristic, where f is the focal length and .theta. is the scanning angle, for the existing optical scanning system, since the distortion becomes as large as 0.3% to 1.2%.
Accordingly, it has not been possible to form an image with high accuracy.